GSAP and Tailwind feature

# GSAP and Tailwind Addition

## Summary

Gsap and tailwind documentation could really help new developers like me

## Examples

Start by reviewing the DevDocs vision in README.md and the existing feature-label issues linked in the report. Determine the intended scope and documentation sources for GSAP and Tailwind CSS; the issue is complete only when the requested documentation is clearly defined and accepted for addition.

索引モデルが issue の本文から書いたものです。